現代通訊系統不斷追求更快的傳輸速度，由著名的雪農理論(Shannon’s Theorem)了解頻寬、訊雜比與通道容量的關係，為了要提高傳輸速度，第五代及未來的通訊系統將要使用到毫米波(mm-Wave)或是更高頻率的頻段。本論文完成應用於第五代陣列無線通訊系統傳輸端之設計、模擬與量測。
由於第五代通訊系統操作於毫米波高頻頻段，空氣中傳輸的損耗相當大，導致有傳輸距離短、無法穿透固體表面等缺點，藉由陣列天線增強傳輸訊號，和波束成型技術增加等效全向輻射功率(Equivalent Isotropic Radiated Power，EIRP)，使傳輸及接收端都有更好的表現。
第二章的陣列貼片天線，使用高頻PCB RT/duroid5880製作，並於毫米波天線實驗室量測，頻率28GHz時得增益12.1dBi、方向性13dBi、效率82%。
第三章的相移器為波束成型的關鍵元件，採用TSMC CMOS 90nm製程，選擇五位元設計11.25度的解析度，使用開關式方便調控及量測，NMOS扮演開關及電容的角色，實現5.35度相位誤差(Phase Error)的五位元相移器。
第四章為可調控增益放大器，採用TSMC CMOS 90nm製程，為了調控增益時有最小的相位變化，加入相位補償機制，藉由電容電感相位變化相反的特性設計，增益調控範圍為6.6dB。
第五章為傳輸端的整合，包括五位元相移器(5-bit Phase Shifter)、可調控增益放大器(Variable Gain Amplifier)、低雜訊放大器(Noise Amplifier)、功率放大器(Power Amplifier)，採用TSMC CMOS 90nm製程，實現26-32.4dB增益、8.9度相位誤差、9.3dBm 1-dB壓縮點輸出功率、功率消耗120.7、面積3mm2。

Fast-growing wireless communication systems demand for extremely high-data-rate transmission. Comprehend the relationship between bandwidth, signal-to-noise ratio, and channel capacity from the famous Shannon’s Theorem. The fifth-generation and future communication systems will use millimeter wave or higher frequency bands. But high-frequency transmissions suffer from several challenges, like more vulnerable to blockage, huge path loss, etc.
Since the 5G technology operate in the millimeter-wave band, the transmission loss quite large, resulting in a very short transmission distance. Phased-array antenna with beamforming technology effectively overcome this challenge. This thesis presents a 28 GHz phased-array transmitter for 5G wireless communications.
The first 28 GHz phased-array antenna was designed and implemented in PCB RT/duroid5880, which is suitable for 5G devices. Measured in the millimeter wave antenna laboratory at NTUST. It has a gain of 12.1 dBi, a directivity of 13 dBi, and antenna efficiency of 82% at 28 GHz.
The second 28 GHz phase shifter plays an important role in beamforming technology has been designed and fabricated on TSMC 90-nm CMOS process. 5-bit switch-type phase shifter design with a resolution of 11.25 degree. The measured rms phase error of 5.3 degree, rms gain error of 2.39 dB, and insertion loss is -18±4.3 dB for all 32 states at 28 GHz. The third 28 GHz variable gain amplifier has been designed and fabricated on TSMC 90-nm CMOS process. A phase compensation circuit is added to minimize phase variation during gain control.
The last work in this thesis integrates the work of the previous chapters and presents a 28 GHz phased-array transmitter, including 5-bit phase shifter, variable gain amplifier, low noise amplifier, and power amplifier in TSMC 90-nm CMOS technology. The transmitter has phase scan and gain control capabilities, which is applicable to 5G micro base stations. The measured gain is 26-32.4 dB, rms phase error of 8.9 degree at 28 GHz. At 1-dB compression point, OP1dB is 9.3 dBm. The power consumption is 120 mW .

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